Rule 12.1 may also be used to obtain alibi discovery with respect to a specific period or incident during a continuing offense. See United States v. Dupuy, 760 F.2d 1492 (9th Cir. 1985); United States v. Vela, 673 F.2d 86 (5th Cir. 1982). If this type of discovery has been sought, the government should not be limited to proving events that took place only during the time frame identified in its demand, on the theory that the information in the demand amounts to a bill of particulars. Ibid. To ensure that the government will not be so limited, the demand should either include the entire time period of the offense or specify that the period indicated is not the entire time period of the offense.
[cited in Criminal Resource Manual 630; JM 9-18.000]